Rear axle steering systems which are mass-produced or are in development for mass production can comprise a control element, for example a variable-length control arm, in particular a transverse control arm, which is driven by means of a motor. To control the motor, as a rule a rotor position sensor is needed. In addition, in such a control system an absolute position sensor can be incorporated, which is designed to determine a translational or axial movement of the control element. To control the motor, a current motor position and also a current motor rotational speed are usually required. These two parameters are determined, for example, by means of a motor position sensor attached on a motor shaft.
DE 10 2010 052 917 A1 discloses a control element for a steering mechanism of a motor vehicle.